Do you really have two equals signs in the first equation? If this is written correct this is the solution:
Plug in 9-6y where you see x in the first equation.
8(9-6y) = 5y = -14
Distribute the 8.
8 times 9 is 72
-6y times 8 is -48y
70-48y = 5y = -14
We can take thse seperately to see if this statement is true
70-48y=5y
add 48y to both sides
70=53y
divide both sides by 53
y=70/53
then we test the second. . .
It looks like something was written incorrectly here. Check your problem and ask again.